In 1947, Norwegian Thor Heyerdahl was a 33-year-old anthropologist and marine biologist who had recently finished a stint fighting in World War II (he served in the Free Norwegian Forces).
Coming out of such a major life experience, he was then able to devote his attention to a personal project that had been 10 years in the making. While working in Polynesia, he became convinced that the Incas of South America had reached islands there long before Asians migrated to them. Backing up his theory were two findings: Drawings of a Polynesian pineapple were discovered inside the ruins of an Inca temple, and the fact that the Incas had the means to build a raft that could sustain an 8,000-km journey across the Pacific Ocean (roughly the distance from Tokyo to Canberra).
Heyerdahl's theory was bold, and it was rejected by the academic community and subsequently every publisher he approached for funds. Of course, minor things like opposition, lack of support and being called "crazy" to his face dampened Heyerdahl's enthusiasm. However, he assembled a motley crew of five men (one of whom was a refrigerator salesman), constructed a raft made of balsa wood (the same material the Incas would have used), and set sail from the Peruvian coast. He christened the raft "Kon-Tiki," after the legendary Inca sun god. Four years later, Heyerdahl turned the expedition into an Oscar-winning documentary and his book recounting Kon-Tiki's exploits, was translated into 67 languages and sold more than 5 million copies worldwide.